Severance offer, what should I ask for? - what worked for you?

I was offered 11 weeks of severance after 11 years as a graphic designer, and I have a few days to sign. Thank you in advance. There is a non-disparagement clause. Did anyone negotiate and succeed?

Read the release carefully. Mine included things I did not expect, like a non-compete.

I asked for two more weeks and a neutral reference. They agreed to the reference and added a week.